Electronic circuit breakers such as described within U.S. Pat. No. 5,151,842 entitled xe2x80x9cSwitchboards and Panelboards Having Interlock and Load Selection Capabilitiesxe2x80x9d are enclosed within closed compartments to which visual access is made to displays, meters and the like to ascertain the status of the enclosed circuit breakers. To prevent unauthorized access to the circuit breaker settings, some type of a locked compartment door is employed.
Air circuit breakers as described within U.S. Pat. No. 3,095,489 entitled xe2x80x9cManual Charging Means for Stored Energy Closing Mechanisms of Electric Circuit Breakersxe2x80x9d and U.S. Pat. No. 3,084,238 entitled xe2x80x9cRatchet Mechanism for Charging a Closing Springs in an Electric Circuit Breakerxe2x80x9d include operating mechanisms that are mainly exposed to the environment. Since the air circuit breakers are rated to carry several thousand amperes of current continuously, the exposure to convection cooling air assists in keeping the operating components within reasonable temperature limits.
When electronic trip unit programmers are used with such exposed air circuit breakers, a circuit breaker cover such as shown in U.S. patent application Ser. No. 08/863,667 filed on May 27, 1997 entitled xe2x80x9cManual Charging Mechanism for Industrial-Rated Circuit Breakerxe2x80x9d is used to cover and protect the electronic components used within the electronic trip units while allowing visual access to the trip unit display.
In the event that adjustments are required with respect to the trip unit settings, some arrangement must be made to allow gated access to the trip unit settings without having to expose the remaining circuit breaker electrical components.
One purpose of the invention is to provide a circuit breaker cover that provides security to the circuit breaker operating components while allowing gated access to the trip unit adjustment knobs for test, adjustment and calibration of the trip unit settings.
An insulative circuit breaker cover is provided with a separate door covering the circuit breaker trip unit programmer unit. A visual access slot is formed in the door for viewing the circuit breaker display and a rating plug access slot is formed therein for inserting the circuit breaker burden resistor. A lockable door allows access to the circuit breaker programmer that houses the trip unit for test, adjustment and calibration thereof.